For decades, a small group of futurists and scientists have been warning us about this moment, and it arrived last week. Three independent research centers, including one at Harvard University, announced the results of experiments that have stunned them and the medical and scientific community: They reversed aging.

We’re not talking about slowing aging with healthier lifestyles, injections, creams or surgery. These researchers made mice younger, and the results were clear.

Building on earlier experiments with stem cells in muscles, they co-mingled the blood of young mice with older mice. The unmistakable result was that the young mice got older and the older mice got younger and lived longer. In later experiments, they achieved the same results by simply injecting the protein contained in young blood that was causing aging to reverse.

Put in human terms, their results would have transformed a 60-year-old into a 20-year-old equivalent. Human trials, using the blood and protein of teenagers, will begin later this year, focusing initially on advanced Alzheimer’s patients. If those prove successful, the greatest revolution in human history will be upon us.

We’ve been extending life for a long time, of course, and particularly during the last 100 years, when life expectancy here increased by about 30 years. Most of that advance resulted from reducing child mortality, improving diets, safer workplaces and continual advances in medicine and disease control.

But that’s all about life extension, which most researchers agree can take us only so far, perhaps to life spans of 120 years or so. Life renewal, or reversing aging, is a profoundly different matter. Extending people’s lives without reversing aging has the unintended consequence of increasing age-related ailments such as cancer, heart disease, dementia, some diseases and disabilities. Reversing aging attacks all of those ailments at their root.

With age reversal, life spans could be extended to 150 to 200 years, during which time other advances that we cannot now foresee almost surely will extend life even further. We don’t have any pictures in our heads for what that looks like, because it’s something we’ve never seen. We don’t have words for it either. “Old” and “aging” carry connotations of decline. But tomorrow’s “old” people almost certainly will be younger than their age suggests because age will become more a measure of time than decline.

Sometimes massive changes in human history are ushered in with sudden events. Thomas Edison’s incandescent lamp in 1879 or Orville Wright’s 120-foot powered flight at Kitty Hawk, N.C., in 1903 are good examples. Others, like the industrial revolution or the digital age we’re now in, wash over us like an oncoming and forceful tide over a longer period of time.

The revolution of life renewal, like the digital one, will come faster than most of us can foresee, and it will make the industrial and digital revolutions look quaint, by comparison.

The social, economic, political and moral implications of life renewal are enormous. Unless births are slowed, population will explode at the same time we’re grappling with global climate change. We’ll have aging societies that are actually younger than their age. Women will have babies at a far older age than is now possible, and family structures eventually could include five or even 10 living generations.

We’ll struggle with who will get life-renewal treatments and what it will cost. Will life renewal be limited, as so much preventative care is now, to only those who can afford it, or will it be available to all?

People will stay in the workplace longer and reinvent their careers every 10 or 20 years, but they’ll also create more new businesses. The definition of retirement age will change. We’ll need term limits in every level of politics, to ensure that a new ruling class doesn’t entrench in power. War and reckless behavior may decline as fewer young people are prepared to risk 100 or 200 years of life.

If all of this seems preposterous to you, imagine what the people of 1903 would have thought if you tried to tell them that within 70 years we would have men on the moon, and within a 10 years people would live 30 years longer, routinely replace joints and carry the knowledge of the world in devices in their pockets. They’d have called you mad.

If you think that these conversations are off in the far-distant future somewhere, think again. This is the discussion we’ll be having with increasing frequency over the next few years and decades. This is not a drill.

Alan Caron, a Waterville native, is president of Envision Maine, a nonprofit organization working to promote Maine’s next economy, and co-author of an upcoming book titled “Maine’s Next Economy.” Email at [email protected]